For the Love of a Castle
by ANGSWIN
Summary: Part 1 of the "Witchcraft, Wizarding, and Worldbuilding" series...Horace Slughorn is overjoyed to be back teaching at Hogwarts because he is one of the few people who really understands her true nature. Therefore, he is looking forward to renewing his relationship with both the Castle and her Headmaster...Written by request for the 2017 Worldbuilding Exchange


_Written for **The Plaid Slytherin** who requested a worldbuilding fic about the magical features of Hogwarts Castle that included Horace Slughorn and a possible HS/AD ship. (I tried to write this story in such a way that this relationship can be read either as a close friendship or a light romance - if you squint.) _

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**For the Love of a Castle**

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 **August 1, 1996**

Horace Slughorn stood at the apparation point right outside of Hogwarts and looked up at the castle that had been his home for fifty years before his retirement from teaching fifteen years ago. At that time, retirement had seemed to be such a good idea. Voldemort had just been defeated by the young Harry Potter. Plus, the very talented Severus Snape, his own former prized pupil, had just finished his Mastery and was ready to take over from him in the dungeon classroom. Therefore, Slughorn had packed up his belongings and bid farewell to the two best friends that he had ever had – Albus Dumbledore and the Castle herself - in order to do some of the things that he wanted and needed to do in life without the constant demands of professorship!

Unfortunately, retirement had not turned out the way that he had planned. Therefore, after just a little persuasion from Albus, he agreed to return and take up his old position again. As he walked up the path to the Castle and started to think about how excited he was to see _her_ again, his mind started to wander down another path…the path of his memories. He started to think about the first time that he walked up to her as a Hogwarts professor… sixty-five years ago…and discovered just how magical she could be!

* * *

 **August 1, 1931**

Young Horace Slughorn was excited. He had just finished his Mastery and had been immediately hired by Headmaster Dippet to become the Potions Master at Hogwarts. Now he was here, walking up to his Alma Mater, to enter her for the first time, not as a student - but as a Professor! He knew that the other teachers had started arriving in the last few days, as well, but he was the only one on this path at the moment. As soon as he reached the imposing front doors, he felt a feathery light touch across his mind, and then the doors opened of their own accord in front of him. Horace looked around interestedly to see who was there to greet him, but the hall was empty. He couldn't help but notice that, despite his solitude, an encompassing _feeling_ of warmth and welcome pervaded his senses anyway as he made his way across the castle to the Headmaster's office to report for duty. He reached Dippet's office much sooner than he had expected, however, noticing that he did so without having to travel many of the twists and turns that he remembered from his student years. He thought that was odd, but shook off the feeling as the Headmaster greeted him with his usual genial calm.

In fact, he had almost put the strange occurrences of his arrival out of his mind when he felt that light tickle across his consciousness again and the Headmaster suddenly proclaimed, "Ah, I see that _She_ has adopted you already, Horace. You should feel honored. She doesn't choose many. In fact, you and young Albus seem to be the only ones that she has favored in quite a while."

Horace was confused. " _She_ , sir?" he asked _._

"Don't you feel it, boy?" Dippet asked, tapping his temple with a slender finger. "The Castle always bonds with the Headmaster of Hogwarts. However, occasionally she bestows that gift upon others, as well. Slughorn, my dear boy, the Castle has chosen you for her own!" With those words, the Headmaster sent a bewildered Horace on his way to his quarters to start preparing for his new life at Hogwarts.

Over the next few days, Horace started to get an idea of what it meant to be adopted by the Castle. It started when he walked into his new chambers for the first time. He grimaced at the cold sparseness of the dungeon accommodations and started to dread the thought of actually living there. However, then he felt that tickle in his mind again. He closed his eyes to analyze the feeling and realized that it felt a lot like Legilimency. When he opened his eyes up again, though, he was amazed to see that his chambers had been transformed! They had gone from cold and austere to warm and luxurious. Comfortable furnishings in his favorite Slytherin-affliated colors now dominated the rooms with other pleasing touches - such as a roaring fire in the hearth and curved walls to help retain the warmth. There was even a platter of his favorite crystallized pineapple and a bottle of perfectly aged mead on the sitting room table. The Castle had read his mind and had given him exactly what he had wanted! He had always known as a student that the Castle had her own brand of magic, as well as some sort of sentience. However, he had never given much thought as to the extent of it. Now, however, he knew something without a doubt. The Castle was _alive_ and for some surprising reason, she liked him! He knew that this was a gift and he wanted to express his gratitude. Therefore, he gently stroked the expanse of wall closest to him and murmured his appreciation. This time the featherlight touch across his thoughts had a definite _pleased_ feeling associated with it. Horace was left with the distinct impression that if the Castle had been a cat, then she would definitely have been purring!

Horace found out quickly that the Castle also had other abilities that he didn't know about as a student. For example, even though she couldn't speak to him in words, she often sent him messages through pictures or feelings. He could always tell when she was _near_ him because he would feel that feathery light touch across his mind. It always felt a bit ticklish when she was feeling playful, warm and encompassing when she was being comforting and loving, or a bit cool if she disapproved of his actions. However, he always respected her and in return she took care of him. For example, he realized that he could always count on running into a handy set of stairs or a corridor that he had never seen before to provide a short cut for him if he was running late for a meal, class, or staff meeting. Handy hidden alcoves were always nearby if he wanted to avoid someone or something in the corridors. The whereabouts of anyone in the Castle were shown to him if he asked. Whenever he found himself in need of them - books from the library, supplies from his storeroom, or snacks from the kitchen were delivered to him after just a thought. Therefore, he knew without a doubt that his personal association with the Castle certainly brought his life to a level of ease and comfort that he had never known before – even as a member of a privileged pureblood family.

The Castle also turned out to be an ally in the classroom. He found this out after a careless fifth year student accidently added eye of skrewt, rather than eye of newt, to an already volatile potion. This caused a small explosion that demolished one side of the classroom and injured several students. The Castle instantly sent House Elves to apparate the affected students to the hospital wing – since they were the only ones who could do so within the Castle's walls. She then rebuilt the side wall of the Potions classroom overnight for Horace, so that his classes could resume the next day.

The Castle wasn't his only friend, though. Horace quickly became acquainted with Albus Dumbledore, the young Transfiguration professor who had started teaching just a few years prior. According to Headmaster Dippet, Albus was also a favorite of the Castle. Once the two young men started to exchange stories, they realized that they did indeed share an affinity with _Her_. Albus had done quite a bit of research on the subject and conjectured that it stemmed back to the Castle's origins when the Four Founders all poured their magic into the very foundations of their new school. Each founder associated with his or her own type of elemental magic: Gryffindor with Fire, Slytherin with Water, Ravenclaw with Air, and Hufflepuff with Earth. The combination of all four of these ancient and powerful elemental magics is what "woke" the Castle up and created her sentience. As for why she had chosen the two of them… "We are just two good looking blokes, I guess!" Albus exclaimed with a twinkle in his bright blue eyes. At those words, they both felt the Castle's amusement touch their minds – and they all shared a warm chuckle.

The years passed by in a comfortable whirlwind of routine and duty for Horace. However, through it all, the Castle and Albus stayed fast as his closest friends and confidantes. The relationship among the three of them had evolved into something much stronger than just a close friendship – even though it soon became clear that the Castle was the anchor between the two men who had very different temperaments and ambitions. Horace, the consummate Slytherin, was content to stay put with the Castle and let others do his legwork for him. His efforts at gathering the best and brightest of his students together in the Slug Club had been amply repaid by a large circle of influential friends and acquaintances who all owed him small "favors" for introducing them to the other members of his circle. However, on the other hand, Albus, the daring Gryffindor, liked to travel, meet new people, and have adventures. Therefore, while Horace gathered his friends and comforts close around him during the summers and school holidays, Albus was out gathering awards, accolades, and a name beyond the walls of Hogwarts. However, whenever he returned back home, both Horace and the Castle were always waiting for him.

Albus eventually succeeded Armando Dippet as Headmaster of Hogwarts and the two men learned about a whole new aspect of the Castle – her bond with the Headmaster. Despite often joking that his favorite part of the bond was the never ending supply of sherbert lemons in the bowl on his desk, Albus found that the Castle had provided him with something much more important. He now possessed several new layers of consciousness when it came to Hogwarts. He suddenly became aware of not just himself and the bond that he shared with Horace and the Castle, but with _everything_ that happened in the Castle and on her grounds. It was as if he was looking through her omnipresent "eyes" all of the time. He knew which students were out after curfew and which ones were snug in their beds (or occasionally in the beds of others). He knew which staff members were having breakfast in the Great Hall and which ones decided to have a tray delivered to them so that they could sit in front of their fire with a good book instead. He knew how many owls were in the owlery at any given moment and what the Giant Squid was doing in the lake. He knew which dangerous creature was currently riding around in Hagrid's coat pocket and which ghost was floating down the Charms corridor. It also meant that he knew when the safety of the Castle was compromised, as well. He knew the instant an accident happened, a ward was breached, or when danger was imminent. Through the gift of the Castle's omniscience, he really knew _everything_!

At first, this overload of extra information threatened to drive him around the twist. In fact, this is when he actually started to use the "Nitwit! Blubber! Oddment! Tweak!" speech at the welcoming feast in reference to some of the things that the Castle was showing to him at that moment. However, he ended up liking that part of the speech so much that he continued to give it every year afterwards – much to the confusion of the students and the dry amusement of the staff. Eventually, though, he learned to tune out what he didn't want or need to see at any given point in time. On the other hand, if he needed to see something in more detail, he could focus on certain events or tune into them as if they were on a Muggle television set or wireless. These new abilities introduced new avenues of both entertainment and trouble into his life. In fact, he often spent hours regaling Horace with stories about the more amusing and/or disturbing events that he had "seen" throughout the day as they relaxed into their usual evening routine in front of the fire after their school duties were done. The Castle, as always, was present during these evenings, as well. Albus knew, through his new bond, that she could exist on several levels, as well. She could multitask and lounge with them in their quarters at the same time that she _chatted_ with the Sorting Hat with whom she shared a type of sibling bond since he had been imbued with the same type of magic that had created her. She could do this while she monitored the House Elves in the kitchen and tested the security wards around the Castle and its grounds that kept them safe from invasions. She could truly do anything and everything - all at the same time!

More decades passed and the trio found that they could survive almost anything together. They made it through all of the troubles that accompanied the deep seated rivalry that always seemed to consume the Slytherin and Gryffindor houses, the ever-changing political climates, the confusion of the Tom Riddle years, the chaos of the Marauders' years, and through Voldemort's first reign of terror. It was then that everything changed, though.

Once it seemed that Voldemort was gone, Horace started to rethink his priorities. For the sake of his vast Slug Club network, he had tried to stay neutral throughout the war. However, he suffered greatly with his guilt over not publically choosing the side of the Light – especially after the deaths of his favorite former student, young Lily Potter and her husband, James. However, in a time where most members of his former Hogwarts house were distrusted, his reputation as a fair and respectable Slytherin renewed his popularity and he was inundated by invitations from former classmates and students, as well as other important and influential people that were connected to him through the former members of his Slug Club. Therefore, after discussing it with Albus and the Castle, he decided that it was finally time to him to leave the school and experience life outside of the Castle walls for a while. Perhaps, he could even do some good in restoring the once honorable name of the House of Slytherin at the same time. Therefore, at the end of the term, he bid a tearful, but hopeful, farewell to his two best friends and headed back out into the world.

* * *

 **August 1, 1996**

Horace stood on the path and blinked back tears as he remembered that goodbye. In the years after his retirement, he had often written long letters to Albus that he knew would be shared with the Castle. He had even gone back occasionally to visit, of course. Also, no matter where he was, every year on his birthday, he received a care package packed with all of his favorite Hogwarts goodies. There was never a note attached, but he knew that they came from the Castle herself. He didn't know how she managed to do it, but he suspected that she enlisted the help of both the house elves and the school owls – since they both came under her jurisdiction.

Thinking of the Castle made him very anxious. He had been unable to visit her for the last couple of years since Voldemort's return. Therefore, he was very eager to see her again. At this thought, he felt like he could wait no longer. He then moved as fast as his little rotund body could go up the path. As he neared her doors, he felt her joyful welcome in his mind and the doors flew open to reveal Albus Dumbledore standing there waiting for him, as well. Horace then knew without a doubt that he had come home!


End file.
